Transparent auto-negotiation of ethernet

ABSTRACT

A system for negotiating Ethernet link settings between interconnected nodes in a network having an Ethernet protocol stack that includes a PCS sub-layer with an auto-negotiation function. The system comprises connecting an intermediate device coupled between two network nodes via optical or copper interfaces, with the link settings between each node and the connected intermediate device being the same, thereby bypassing the auto-negotiation of the PCS sub-layer in the intermediate device. The intermediate device may transparently send negotiation messages from each node to the other during the link negotiation phase without interacting with those messages. Instead of the intermediate device, a single form pluggable (SFP) device may be connected between the two network nodes via optical or copper interfaces on the network side and via an SFP slot on the device side.

This application is a continuation of U.S. patent application Ser. No.15/287,182, filed Oct. 6, 2016, now allowed, which is a continuation ofU.S. patent application Ser. No. 14/698,407, filed Apr. 28, 2015, nowU.S. Pat. No. 9,491,053, which is a continuation of and claims priorityto U.S. patent application Ser. No. 13/608,476, filed Sep. 10, 2012, nowabandoned, each of which is hereby incorporated by reference herein inits entirety.

FIELD OF THE INVENTION

The present invention relates to the transparent negotiation of Ethernetsettings between a pair of end devices connected to each other via anintermediate device, where the intermediate device does not participatein the negotiation phase between the two end devices, but inherits theEthernet settings negotiated by the two end devices and initializes itsEthernet ports according to the results of the negotiation between thetwo end devices.

BACKGROUND OF THE INVENTION

When inserting a new device in a network, particularly when the newdevice is inserted between a pair of devices that would otherwise bedirectly connected together over Ethernet, there is a risk that the newdevice may impact the results of a negotiation of the Ethernet settingsbetween the original pair of devices.

For instance, a disparity in the negotiation of the settings could occurwhen only one device is up when the intermediate device is started. Thiscould result in the negotiation of a half-duplex Ethernet connection onone port of the intermediate device while the other port of theintermediate device negotiates a full-duplex Ethernet connection withthe other remote device.

Another problem to handle is when there is only a single deviceconnected to the intermediate device at a given time. Under such ascenario, the device connected to the intermediate device shall be ableto operate at the highest possible speed supported by that said deviceand not have to wait for a second device to be connected to theintermediate device before it can negotiate the settings of the Ethernetconnection.

In a typical 1000BaseT Ethernet protocol stack, the Physical CodingSub-layer (PCS—see FIG. 3 “37-1—Location of the Auto-Negotiationfunction” from the IEEE 802.3-2008 standard) is responsible for thenegotiation of the Ethernet settings for a specific Ethernet port on adevice. The harmonization of the negotiation of the Ethernet settingsfor multiple ports in a single device is not covered by the IEEE802.3-2008 standard.

There is a need to allow the ability to inspect and operate on Ethernetframes received over any of the ports of an intermediate device once theauto-negotiation phase is completed.

SUMMARY

In accordance with one embodiment, a system for negotiating Ethernetlink settings between interconnected nodes in a network, theinterconnected nodes having an Ethernet protocol stack that includes aPCS sub-layer with an auto-negotiation function comprises intermediatedevice coupled between two network nodes via optical or copperinterfaces, with the link settings between each node and the connectedintermediate device being the same, thereby bypassing theauto-negotiation function of the PCS sub-layer inside the intermediatedevice. The intermediate device may transparently send negotiationmessages from each node to the other during the link negotiation phasewithout interacting with those messages.

In one implementation, a pair of network devices are attached to theintermediate device, and the intermediate device includes at least twophysical ports and a management module that sets the two physical portsto Ethernet settings negotiated between the pair of network devices.Normal Ethernet functioning may be resumed after the negotiating of thelink settings is complete.

This method allows the negotiation of the Ethernet settings between apair of devices attached to the intermediate device to take placewithout the intermediate device taking part in the auto-negotiationphase between the pair of devices attached to the Ethernet ports of theintermediate device. This is achieved by bypassing (or modifying) theauto-negotiation sub-module in the PCS sub-layer where the configurationcodes received on one of the Ethernet port of the intermediate deviceare directly sent to the PCS sub-layer transmit function on the otherport of the intermediate device, bypassing the auto-negotiationsub-module defined by the IEEE 802.3-2008 standard for these Ethernetports.

An additional management module is needed to monitor the negotiationexchange between the pair of devices attached to the intermediate devicein order to set the two physical Ethernet ports of the intermediatedevice to the Ethernet settings negotiated between the pair of devicesattached to the intermediate device. This is important since theintermediate device may have to process Ethernet frames exchangedbetween the pair of devices to perform Service OAM and other functionsand the Ethernet settings of the two ports in the intermediate deviceneed to exactly match the Ethernet configuration negotiated between thepair of devices connected to the intermediate device.

When there is only one device attached to the intermediate device, thenegotiation shall proceed as per the IEEE 802.3-2008 standard as if theattached device was to negotiate with itself.

Finally, all other Ethernet frames need to flow through the MACsub-layer of the individual Ethernet ports of the intermediate device(in receive and/or transmit mode).

In a modified embodiment, a method of negotiating Ethernet link settingsbetween interconnected nodes in a network comprises connecting a singleform pluggable (SFP) device between two network nodes via optical orcopper interfaces on the network side and via an SFP slot on the deviceside, and negotiating the link settings identically between each nodeand the connected SFP device. The SFP device may transparently sendnegotiation messages from each node to the other during the linknegotiation phase without interacting with those messages.

In one implementation, the SFP device includes two physical ports, andwhich includes a pair of network devices attached to said SFP device,and a management module that sets the two physical ports to Ethernetsettings negotiated between the pair of network devices. Here again,normal Ethernet functioning may be resumed after a link negotiationsequence is complete

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may best be understood by reference to the followingdescription taken in conjunction with the accompanying drawings.

FIG. 1 is a simple network where two devices are connected with anintermediate device

FIG. 2 is a simple network where two devices are connected with anintermediate SFP

FIG. 3 illustrates the sub-layers corresponding to the Data Link layeras defined in the generic OSI model.

FIG. 4 illustrates the protocol sub-layers of the Ethernet Data Linkprotocol

FIG. 5 illustrates how one of the Ethernet port of the intermediatedevice interfaces with the host with the SFP slot rather than with aphysical Ethernet port (copper or optical)

FIG. 6 illustrates how the PCS sub-layer is broken into distinctfunctional modules.

FIG. 7 illustrates how the Auto-negotiation function of the PCSsub-layer is replaced or modified to support this invention.

FIG. 8 illustrates an alternate implementation with changes to theinteractions and functions of the Switch Modules, Management module andthe interface with the PCS Transmit and Receive functions

FIG. 9 illustrates an alternate implementation where the Switch Modulesused previously are integrated as part of the Management module thatinterfaces directly with the PCS Receive function and with the PCSTransmit function.

FIG. 10 illustrates an alternate implementation where the managementmodule handles the interfacing between the MAC sub-layer and the PCSReceive and Transmit functions.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS

Although the invention will be described in connection with certainpreferred embodiments, it will be understood that the invention is notlimited to those particular embodiments. On the contrary, the inventionis intended to cover all alternatives, modifications, and equivalentarrangements as may be included within the spirit and scope of theinvention as defined by the appended claims.

The invention is aimed at allowing an intermediate device to facilitatethe interconnection and the automatic negotiation of the Ethernetsettings (e.g speed, half or full duplex, master or slave for clock orother parameters) between a pair of devices as if these devices weredirectly interconnected by a standard Ethernet cable. By inserting anintermediate device between the pair of devices, it is possible to offerService OAM and other functions without disrupting the operation of thepair of devices. This transparent mode of operation of the intermediatedevice includes enabling a totally transparent negotiation of theEthernet settings for each connection as if they were a simple Ethernetcable directly connecting the pair of devices.

An example of this can be seen in FIG. 1 where device A 110 and device B120 are interconnected via Ethernet connections 104 and 105 to theintermediate device 101. More specifically, device A 110 is connected tothe intermediate device 101 via Ethernet port 102 and device B 120 isconnected to the intermediate device 101 via Ethernet port 103. Asdescribed further below, the negotiation of the Ethernet settings takesplace transparently between the devices 110 and 120 as if they wereconnected directly via a single Ethernet cable.

FIG. 2 illustrates another embodiment of the invention where theintermediate device is embodied as a standard-based Single FormPluggable (SFP) device with an embedded FPGA device and an optional CPUmodule (which can be internal or external to the FPGA module). Device A210 is a network node with a standard-based SFP slot. An SFP module 201is inserted in device A 210 and acts as a transparent intermediatedevice between device A 210 and device B 220. The SFP module 201incorporates a pair of Ethernet ports. The Ethernet port 202 interfacesto device A 210 in compliance with the physical connector and signalingdefined by the SFP standard. Ethernet port 203 uses a standard Ethernetconnector (such as an RJ-45 or an optical connector) to connect todevice B 220 over either a copper or optical fibre 204. The functionsand services offered by the SFP module 201 are analogous to theintermediate device 101 described in FIG. 1.

The negotiation techniques described below apply to both of theseembodiments and any alternative embodiment using an intermediate deviceknown to someone skilled in the art unless explicitly stated otherwise.

The IEEE 802.3-2008 standard defines the operation of the Ethernetprotocol stack at various operating speeds, including Gigabit Ethernet(also referred to as 1000BaseT Ethernet). FIG. 3 is extracted andcorresponds to FIG. 37-1 from the IEEE 802.3-2008 standard andillustrates the sub-layers corresponding to the Data Link layer asdefined in the generic OSI model. In a typical 1000BaseT Ethernetprotocol stack, the Physical Coding Sub-layer (PCS) is responsible forvarious functions, including the Auto-Negotiation function of theEthernet settings for the Ethernet connection carried over a specificEthernet port. The Auto-negotiation function of the PCS sub-layer isdefined in the standard to cover the operation of a single Ethernet portat a time. As such, the IEEE 802.3-2008 standard does not define how tohandle the harmonization of the negotiation of the Ethernet settings formultiple ports in a single device.

The Ethernet Data Link protocol layer is made up of several protocolsub-layers. As seen in FIG. 4, the Medium Independent Interface (MDI)401 is responsible for the physical interconnection to the Ethernetcable. Frequently, this is achieved via the popular RJ-45 interface,although optical and other medium may also be used. The Physical MediumDependent (PMD) sub-layer 402 is responsible for presenting a mediumindependent interface to the Physical Medium Attachment (PMA) sub-layer403. The PMA sub-layer interfaces with the Physical Coding Sub-layer(PCS) 404 that is responsible, amongst other things, for theauto-negotiation settings of the Ethernet connection over the Ethernetport. When operating at 1000BaseT speeds, the auto-negotiation phase isa mandatory feature as specified by the IEEE 802.3-2008 standard. Whilenegotiation codes are handled inside the PCS sub-layer 404, all otherEthernet frames are passed to (or received from) the Media AccessControl (MAC) sub-layer 405. When looking at each sub-layer of theEthernet protocol stack in FIG. 4, as is known in the art and as per thedefinition of the Ethernet standard, it should be noted that eachsub-layer further includes a Receive and a Transmit function.

FIG. 5 illustrates how one of the Ethernet ports of the intermediatedevice interfaces with the host with the SFP slot rather than with aphysical Ethernet port (copper or optical) when an SFP module isinserted in an SFP slot of a host device. The SFP module 550 interfacesto the Host device 530 via its SFP connector 540. The Ethernetsub-layers on the SFP module 550 are limited to a subset of the layersillustrated by FIG. 4 above. The MAC sub-layer 555 interfaces in atraditional way to the PCS sub-layer 554 that in turn interfaces to thePMA sub-layer 553. The lower interface of the PMA sub-layer 553 uses the1000Base-X encoding to communicate over the SFP connector 540. TheEthernet sub-layers on the Host device 530 are similar. The MACsub-layer 535 interfaces in a traditional way to the PCS sub-layer 534that in turn interfaces to the PMA sub-layer 533. The lower interface ofthe PMA sub-layer 533 uses the 1000Base-X encoding to communicate overthe SFP connector 540.

The negotiation of the Ethernet settings between a pair of devicesattached to an intermediate device can take place without involving theauto-negotiation function usually performed at the PCS sub-layer in theEthernet protocol stack for each port of the intermediate deviceconnected to the pair of external devices 110 and 120 in FIG. 1.

FIG. 6 illustrates how the PCS sub-layer 600 is broken into distinctfunctional modules. The PCS Receive function 601 passes Ethernetnegotiation codes received from the PMA sub-layer to theAuto-negotiation function 603. Incoming Ethernet data frames from thePMA sub-layer are passed directly to the MAC sub-layer (not shown inFIG. 6). The PCS Transmit function 602 passes Ethernet negotiations codefrom the Auto-negotiation function 603 to the PMA sub-layer for eventualtransmission to the remote device with which it is negotiating theEthernet settings. The PCS Transmit function 602 is also responsible forEthernet data frames originating from the MAC layer (not shown in FIG.6). The transparent auto-negotiation of the Ethernet settings isperformed as if the PCS Auto-negotiation function 603 inside each of thepair of external devices (from the point of view of an intermediatedevice) were directly interconnected via an Ethernet cable. This isachieved by bypassing (or modifying) the Auto-negotiation function 603in the PCS sub-layer 600 of each Ethernet port of the intermediatedevice where the configuration codes received on one of the Ethernetport are directly sent to the PCS sub-layer transmit function 602 of theEthernet protocol stack of the other Ethernet port on the intermediatedevice, bypassing the Auto-negotiation function 603 defined by the IEEE802.3-2008 standard.

FIG. 7 illustrates an embodiment of the Auto-negotiation function of thePCS sub-layer. The full Ethernet protocol stack is shown for a pair ofEthernet ports (700, 720). The PMD sub-layer 701 and the PMA sub-layer702 operate as per the IEEE 802.3-2008 standard. The PCS sub-layer ismodified by replacing the Auto-negotiation function normally found in astandard implementation of the PCS sub-layer with a new function thatacts as a programmable switch for the 8-bit interface provided by thePMA sub-layer. The switch function 709 will by default be set in theCONFIGURATION mode. Any received /C/ and /I/ ordered sets received overthe PCS Receive function 707 will be passed to a switch 709, and theswitch 709 will be configured by the Management module 710 to forwardall ordered sets /C/ and /I/ received over the PCS Receive function 707to the PCS Transmit function 728 of the other Ethernet port 720. Theswitch 709 will also forward the Ethernet ordered sets /C/ and /I/ tothe Management module 710 responsible for determining when theauto-negotiation phase between the devices attached to port 700 and port720 of the intermediate device is completed. The same behaviour takesplace for the second Ethernet port. The switch 729 is configured by theManagement module 710 to forward all /C/ and /I/ ordered sets receivedover the PCS Receive function 727 to the PCS Transmit function 708 ofthe other Ethernet port 700. The switch 729 will also forward the /C/and /I/ ordered sets to the Management module 710 responsible fordetermining when the auto-negotiation phase between the devices attachedto port 700 and port 720 of the intermediate device is completed. TheManagement module will analyze the ordered sets /C/ and /I/ it receivesfrom switch 709 and from switch 729 to learn the Ethernet settings asthe auto-negotiation phase progresses between the device attached toport 700 and the device attached to port 720. The Management module willdetermine that the auto-negotiation process is completed when it sees a/I/ ordered set from either of the devices attached to ports 700 and 720over their respective PCS Receive functions 707 and 727.

Upon detecting that the auto-negotiation phase is completed, themanagement module 710 programs the switch 709 and the switch 729 in DATAmode to stop forwarding the /C/ and /I/ ordered sets to the PCS Transmitfunction (708 and 728) of the other Ethernet port (700, 720). Switch 709will be programmed to send all /R/, /S/, /T/ and /V/ ordered sets to theMAC Sub-layer 705, and the Switch 729 will be programmed to send all/R/, /S/, /T/ and /V/ ordered sets to the MAC Sub-layer 725. Both switch709 and switch 729 will continue to forward all /I/ and /C/ ordered setsto the Management module 710 to detect whether one of the devicesattached to port 700 or port 720 needs to re-enter in theauto-negotiation phase. When the Management module 710 detects that anew auto-negotiation phase needs to take place, it will program switch709 and switch 729 to operate in the CONFIGURATION mode.

Once the auto-negotiation phase is completed, the Management Module 710needs to set the parameters of the Ethernet ports of the intermediatedevice. Particular attention is needed when an Ethernet port of theintermediate device operates over copper. If the remote device attachedto such an Ethernet port is assigned the role of Master (for theclocking), then the corresponding Ethernet port of the intermediatedevice shall be configured in Slave mode. Otherwise, if the remotedevice is assigned the role of Slave, then the corresponding Ethernetport of the intermediate device shall be configured in Master mode. Ifthe pair of Ethernet ports (700, 720) of the intermediate device bothoperate over copper, one Ethernet port (in the pair of ports) will beconfigured as a Master, and the other Ethernet port (in the same pair ofports) will be configured as a Slave. The Management module 710 alsoneeds to make sure both Ethernet ports (700, 720) are set to thenegotiated duplex settings: Full or Half.

If the Ethernet ports of the intermediate device are made up of anoptical Ethernet port and of a copper Ethernet port, the ManagementModule 710 will need to intercept all of the /C/ ordered sets to makesure that the Master/Slave mode and the Duplex settings negotiation onlytake place on the Ethernet over copper port. This can be achieved byprogramming the Switches 709 and 729 to pass all of the /C/ ordered setsto the Management module 710 instead of simply relaying the /C/ to thePCS transmit function 708 or 728 of the other Ethernet port.

When there is only one device attached to the intermediate device, thenegotiation shall proceed as per the IEEE 802.3-2008 standard as if theattached device was to negotiate with itself. Looking again at FIG. 7and assuming that the device is attached to port 700, the Switch 709will initially be programmed by the Management module 710 inCONFIGURATION mode to forward the /C/ and /I/ ordered sets received overthe PCS Receive function 707 to the PCS Transmit function 708 toloopback the /C/ and /I/ ordered sets back to the device on port 700.The Switch 709 will also be programmed to forward the /C/ and /I/ordered sets to the Management module 710 to allow it to determine theend of the auto-negotiation phase and to program the Switch 709 in DATAmode to stop forwarding to the PCS Transmit function 708 and insteadforward the /R/, /S/, /T/ and NI ordered sets to the MAC sub-layer 705and the Management module 710. Alternatively, if the single device isattached to port 720, the Management module 710 will program the Switch729 in CONFIGURATION mode to forward the /C/ and /I/ ordered setsreceived over the PCS Receive function 727 to the PCS Transmit function728 to loopback the /C/ and /I/ ordered sets back to the device on port720. The Switch 729 will also be programmed to forward the /C/ and /I/code sets to the Management module 710 to allow it to determine the endof the auto-negotiation phase and to program the Switch 729 in DATA modeto stop forwarding to the PCS Transmit function 728 and instead forwardthe /C/ and /I/ code sets to Management module 710.

The replacement of the Auto-negotiation function of the PCS sub-layer inFIG. 7 and described above may also be achieved by other embodiments.

In an alternate embodiment shown in FIG. 8, the interactions andfunctions of the Switch Modules 809 and 829 with the Management module810 and the interface with the PCS Receive function 807 and 827 and withthe PCS Transmit function 808 and 828 is different from FIG. 7. Morespecifically, the PCS Receive function 807 and 827 includes the abilityto detect the type of Ethernet ordered sets and can forward the /R/,/S/, /T/ and /V/ data ordered sets directly to the MAC sub-layer 805(for PCS Receive function 807) and 825 (for PCS Receive function 827).All other ordered sets /C/ and /I/ will be forwarded to the Switchfunction (809, 829) in order to be replicated on the other Ethernet port(800, 820) and will also be forwarded to the Management module 810 tokeep track of the state of the auto-negotiation. PCS Receive function807 will forward the /C/ and /I/ ordered sets to Switch 809 that will inturn forward the ordered sets to the Management module 810 and to thePCS Transmit function 828. PCS Receive function 827 will forward the /C/and /I/ ordered sets to Switch 829 that will in turn forward the orderedsets to the Management module 810 and to the PCS Transmit function 808.The MAC sub-layer will use the PCS Transmit function directly for all/R/, /S/, /T/ and /V/ ordered sets. MAC sub-layer 805 will interfacedirectly with PCS Transmit function 808, and MAC sub-layer 825 willinterface directly with PCS Transmit function 828. The behavior or theother Ethernet sub-layers (PMA, PMD and MDI) remains the same as thedescription of FIG. 7.

Once the auto-negotiation phase is completed, the Management Module 810needs to set the parameters of the Ethernet ports (800, 820) of theintermediate device as per FIG. 7.

If the Ethernet ports of the intermediate device are made up of anoptical Ethernet port and of a copper Ethernet port, the ManagementModule 810 will need to intercept all of the /C/ ordered sets to makesure that the Master/Slave mode and the Duplex settings negotiation onlytake place on the Ethernet over copper port. This can be achieved byprogramming the Switches 809 and 829 to pass all of the /C/ ordered setsto the Management module 810 instead of simply relaying the /C/ to thePCS transmit function 808 or 828 of the other Ethernet port.

In an alternate embodiment shown in FIG. 9, the Switch Modules usedpreviously (see FIG. 7 and FIG. 8) are integrated as part of theManagement module 910 that interfaces directly with the PCS Receivefunction 907 and 927 and with the PCS Transmit function 908 and 928.More specifically, the PCS Receive function 907 and 927 includes theability to detect the type of Ethernet ordered sets and can forward the/R/, /S/, /T/ and /V/ data ordered sets directly to the MAC sub-layer905 (for PCS Receive function 907) and 925 (for PCS Receive function927). All other ordered sets /C/ and /I/ will be forwarded to theManagement module 910 in order to be replicated on the other Ethernetport (900, 920) and to keep track of the state of the auto-negotiation.PCS Receive function 907 will forward the /C/ and /I/ ordered sets tomanagement module 910 that will in turn forward the ordered sets to thePCS Transmit function 928. PCS Receive function 927 will forward the /C/and /I/ ordered sets to Management module 910 that will in turn forwardthe ordered sets to the PCS Transmit function 908. The MAC sub-layerwill use the PCS Transmit function directly for all /R/, /S/, /T/ and/V/ ordered sets. MAC sub-layer 905 will interface directly with PCSTransmit function 908, and MAC sub-layer 925 will interface directlywith PCS Transmit function 928. The behavior or the other Ethernetsub-layers (PMA, PMD and MDI) remains the same as the description ofFIG. 7.

Once the auto-negotiation phase is completed, the Management Module 910needs to set the parameters of the Ethernet ports (900, 920) of theintermediate device as per FIG. 7.

In a final alternate embodiment shown in FIG. 10, the Management module1010 handles the interfacing between the MAC sub-layer and the PCSReceive and PCS Transmit functions. More specifically, the PCS Receivefunction 1007 and 1027 forward all Ethernet ordered sets to theManagement module 1010 that will determine the type of ordered setsreceived. The Management module 1010 will relay /C/ and /I/ ordered setsto the other Ethernet port. /C/ and /I/ ordered sets received from PCSReceive function 1007 will be forwarded to PCS Transmit function 1028,and /C/ and /I/ ordered sets received from PCS Receive function 1027will be forwarded to PCS Transmit function 1008. /R/, /S/, /T/ and /V/ordered sets received by the Management module 1010 from the PCS Receivefunction 1007 will be forwarded to the MAC sub-layer 1005, and /R/, /S/,/T/ and /V/ ordered sets received from the MAC sub-layer 1005 will bepassed to the PCS Transmit function 1008. /R/, /S/, /T/ and /V/ orderedsets received by the Management module 1010 from the PCS Receivefunction 1027 will be forwarded to the MAC sub-layer 1025 and /R/, /S/,/T/ and /V/ ordered sets received from the MAC sub-layer 1025 will bepassed to the PCS Transmit function 1028. The behavior or the otherEthernet sub-layers (PMA, PMD and MDI) remains the same as thedescription of FIG. 7.

Once the auto-negotiation phase is completed, the Management Module 1010needs to set the parameters of the Ethernet ports (1000, 1020) of theintermediate device as per FIG. 7.

The embodiments described above can be implemented inside a single FPGAdevice. Alternatively, they may be implemented between a plurality ofFPGA devices and/or a general purpose CPU. It should be noted that thegeneral purpose CPU may alternatively be implemented inside an FPGAdevice (for instance, a NIOS module in an ALTERA FPGA).

While particular embodiments and applications of the present inventionhave been illustrated and described, it is to be understood that theinvention is not limited to the precise construction and compositionsdisclosed herein and that various modifications, changes, and variationsmay be apparent from the foregoing descriptions without departing fromthe spirit and scope of the invention as defined in the appended claims.

The invention claimed is:
 1. A system for negotiating Ethernet settingsin a network, said system comprising: a first network device and asecond network device; an intermediate device connected to said firstnetwork device and said second network device, said intermediate devicecomprising: a first network interface coupled to said first networkdevice and a second network interface coupled to said second networkdevice, said first network interface and said second network interfaceeach comprising an Ethernet PCS sub-layer; a first switch coupled tosaid first network interface, a management module, and said secondnetwork interface, said first switch for passing firstauto-configuration codes to said management module and said Ethernet PCSsub-layer of said second network interface until said management moduledetects that a first auto configuration is completed; a second switchcoupled to said second network interface, said management module, andsaid first network interface, each of said first and second switch forpassing one or more second auto-configuration codes to said managementmodule and said Ethernet PCS sub-layer of each of said second and firstnetwork interface, respectively, until said management module detectsthat said first and a second auto-configuration is completed; and saidmanagement module programming said first and said second switch into adata mode and configuring a protocol stack of said intermediate deviceto be compatible with said first and second auto-configuration codesonce said management module detects that said first and secondauto-configuration are completed.
 2. The system of claim 1, wherein saidintermediate device is a small-form factor pluggable (SFP) transceiver.3. The system of claim 2, wherein said SFP has one port connected insaid first device and another port connected to the network.
 4. Thesystem of claim 2, wherein said SFP transceiver is an opticaltransceiver.
 5. The system of claim 1, wherein said first device andsaid second device are connected to said intermediate device via aninterface selected from an optical interface, a copper interface, and acombination thereof.
 6. The system of claim 1, wherein said Ethernetsettings are selected from said group consisting of speed, half or fullduplex, master clock, slave clock, and other parameters.
 7. The systemof claim 1, wherein said intermediate device comprises afield-programmable gate array (FPGA), central processing unit (CPU), orcombination thereof.
 8. A method for negotiating Ethernet settings on anintermediate device located between a first and a second device in anetwork, said method comprising: receiving first auto-configurationcodes from said first device on a first network interface on saidintermediate device, said first network interface comprising an EthernetPCS sub layer; receiving second auto-configuration codes from saidsecond device on a second network interface on said intermediate device,said second network interface comprising an Ethernet PCS sub-layer;transmitting said first auto-configuration codes to said Ethernet PCSsub-layer of said second network interface and a management module via afirst switch coupled between said first network interface, saidmanagement module, and said second network interface, until a firstauto-configuration is completed; transmitting said secondauto-configuration codes to said Ethernet PCS sub-layer of said firstnetwork interface and said management module via said first and a secondswitch coupled between said first network interface, said managementmodule, and said second network interface located on said intermediatedevice until said first and a second auto-configuration is completed;and programming, by said management module, said first switch and saidsecond switch into a data mode and configuring a protocol stack of saidintermediate device to be compatible with said first and secondauto-configuration codes once said management module detects that saidfirst and second auto-configuration are completed,.
 9. The method ofclaim 8, wherein said intermediate device is a small-form factorpluggable (SFP) transceiver.
 10. The method of claim 9, wherein said SFPhas one port connected in the first device and another port connected tothe network.
 11. The method of claim 9, wherein said SFP transceiver isan optical transceiver.
 12. The method of claim 9, wherein said firstdevice and said second device are connected to said intermediate devicevia an interface selected from an optical interface, a copper interface,and a combination thereof.
 13. The method of claim 8, wherein saidEthernet settings are selected from the group consisting of speed, halfor full duplex, master clock, slave clock, and other parameters.
 14. Themethod of claim 8, wherein said intermediate device comprises afield-programmable gate array (FPGA), central processing unit (CPU), orcombination thereof.